Electron scattering by atomic chains: Multiple-scattering effects.
Electron scattering by atomic chains: Multiple-scattering effects.
复制标题
原子链的电子散射：多重散射效应。
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
Van Hove MA
中科院分区：
文献类型：
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作者：
Xu;Barton;Van Hove MA
电子沿沿着原子链运动的多重散射效应对于确定表面结构是重要和有用的，特别是在中等能量范围内（200 char 21 {}1000 eV）。这适用于基于弹性电子衍射的技术，例如中等能量电子衍射，以及基于“二次”电子的角度分辨检测的技术，例如光电子、俄歇电子和其他电子。两种新的方法来计算多重散射振幅的链推导和用于显示如何多重散射沿着链的原子产生聚焦，散焦，放大，和层相关的增强，可以有效地用于结构测定。在许多条件下，沿着核间轴沿着的强前向聚焦峰占主导地位：这是一种单散射效应。然而，多重散射可以完全散焦这样的前向聚焦峰，而其他干涉效应产生额外的散射峰，不具有核间轴的方向。此外，由此可见，通过常规俄歇电子能谱法进行的表面成分分析对用于产生俄歇发射的电子束的入射方向非常敏感。
Multiple-scattering effects of electrons traveling along atomic chains are shown to be important and useful for surface structure determination, especially in the medium-energy range (200char21{}1000 eV). This applies to techniques based on diffraction of elastic electrons, such as medium-energy electron diffraction, as well as to techniques based on the angle-resolved detection of ``secondary' electrons such as photoelectrons, Auger electrons, and other electrons. Two new methods for computing multiple-scattering amplitudes for chains are derived and used to show how multiple scattering along chains of atoms produces focusing, defocusing, amplification, and layer-dependent enhancements that can be put to effective use in structure determination. Strong forward-focusing peaks along internuclear axes are dominant under many conditions: this is a single-scattering effect. However, multiple scattering can totally defocus such forward-focused peaks, while other interference effects produce additional scattering peaks that do not have the direction of an internuclear axis. In addition, it follows that surface composition analysis by conventional Auger-electron spectroscopy can be quite sensitive to the incident direction of the electron beam used to produce Auger emission.